1. Field of the Invention
This invention relates to an electric operating device for actuating a handle of a circuit breaker electrically.
2. Description of the Related Art
A conventional electric operating device for a circuit breaker will be described with reference to FIGS. 19(a) through 23, which is disclosed in Published Unexamined Japanese Patent Application No. Hei-4-6727 for instance. FIGS. 19(a) through 19(d) are perspective views of the conventional device, FIG. 20 is a sectional view showing the conventional device, FIG. 21 is an enlarged perspective view showing an operating member and a moving piece in the conventional device, FIG. 22 is an explanatory diagram for a description of the operation of the operating member, and FIG. 23 is a circuit diagram showing the control circuit of a drive section.
More specifically, FIG. 19(a) shows a state of the electric operating device in which an operating part 20 of an operating member 2 is disengaged from a handle 4. That is, the operating part 20 of the operating member 2 is manually pushed toward a body 1 of the device to move a hole 34 formed in the operating member 2 towards a protrusion 33 thereby to disengage the operating part 20 from the handle 4 (See FIG. 21). When the electric operating device is in this state, the handle 4 can be operated manually, and a power switch 25 (FIG. 23) has been turned off by the operating member 2, so that a drive section 13 (FIG. 23) is not operated even if a remote signal is issued.
FIG. 19(b) shows another state of the electric operating device that the operating member 2 is pulled out in the direction of an arrow shown therein, and the handle 4 is at the "off" position where the operating member 2 engages with the handle 4 which is held in the space formed in the operating part 20 as shown in FIG. 22(a). In this state, the operating member 2 is away from the power switch 25, and therefore current is applied to a control circuit shown in FIG. 23, so as to make the drive section 13 operative.
When a remote "on" switch 35 is closed, a remote signal is applied to the control circuit of the drive section 13, to set the handle 4 at the "on" position. As a result, an electric motor 15 is rotated in the direction of the arrow R shown in FIG. 20, so that the protrusion 33 of the moving body 17 is moved through a threaded shaft 16 and a driven body 21 in the direction of the arrow X; that is, the operating member 2 is moved through the hole 34 in the same direction, so that the handle 4 is set at the "on" position by the operating part 20 as shown in FIG. 19(c) and FIG. 22(b). At the same time, a position detecting switch 27 is held depressed by a switching operating part 26. Hence, the motor 15 is rotated in the opposite direction, and the moving body 17 is therefore moved in the reverse direction, and accordingly the operating member 2 is also moved in the opposite direction. The operating member 2 is stopped when the switch operating part 26 abuts against another position detecting switch 28, as shown in FIG. 22(c) (cf. the curved arrow in FIG. 19(c)). In this case, the distance between the positions of the moving member 2 in FIGS. 22(b) and 22(c) is set equal to the range of movement between the "on" position of the handle 4 and a trip display position. The operating part 20 of the operating member 2 has a width corresponding to the distance between the "on" position of the handle 4 and the trip display position, and therefore the handle 4 will not be pushed towards the "off" position.
Since the handle 4 is at the "on" position, the circuit breaker 3 is turned on, thus allowing an electric current to flow in an electric circuit connected thereto. If over-current flows in the electric circuit, the circuit breaker 3 trips, so that the handle 4 is moved from the "on" position to the trip display position. In this case, the handle 4 is moved inside the operating part 20 as indicated by the arrow in FIG. 19(d) or as indicated by the phantom line in FIG. 22(c); however, the operating member 22 is not moved. The circuit breaker thus tripped can be reset by moving the handle 4 to the "off" position.
In order to move the handle 4 from the "on" position to the "off" position, or to reset the same, a remote "off" switch 36 is closed, (FIG. 23) so that the motor 15 is rotated in the direction of the arrow S to thereby move the driven body 21 and the operating member 2 in the direction of the arrow Y; that is, the handle 4 is moved to the "off" position as shown in FIG. 22(d). In this operation, the driven body 21 abuts against another position detecting switch 30, (FIG. 23) and moves in the opposite direction. As the driven body moves on, the switch operating part 26 depresses another position detecting switch 29 before the position where the on-operation of the handle 4 is effected, so that the motor 15 is stopped, and the operating member 2 is stopped as shown in FIG. 22(e) which is of the same as FIG. 22(a).
With such a conventional electric operating device as described above, in order to display the tripping of the circuit breaker 3, the operating part including the operating handle 4 requires a space larger than the allowable length from the "on" position to the trip display position, and, after having achieved the "on" operation, the operating handle 4 must be returned a distance equal to the allowable length.
Hence, the conventional electric operating device suffers from the following difficulties:
(1) Since, after having achieved the "on" operation, the operating part must be returned the distance equal to the allowable length as was described above, the position of the operating part must be controlled with high accuracy, and the control circuit is unavoidably intricate.
(2) Since it is necessary to move the operating part additionally as much as the distance equal to the allowable length, additional spaces must be provided for the operating part in the directions of "on" and "off" operations.